Pattern attachment



April 1, 1969 J. 'r. SHORT PATTERN ATTACHMENT Sheet 1 of 3 Filed April 18, 1967 INVENTOR Joe 7. Short 1 [m], fluwwzw A T TOR NE YS J. 'T. SHORT PATTERN ATTACHMENT April 1, 1969 Z of 3 Sheet Filed April 18, 1967 FIGTZ RELAY RELAY JOE T. SHORT FIGS ATT mm J- T. SHORT PATTERN AT TACHMENT April 1, 1969 Sheet 3 of3 Filed April 18, 1967 SUPPLY POWER oo INVENTOR JOE T. SHORT ONE- SHOT MULTIVIBRATOR 87 j zam 51444, S

United States Patent 3,435,787 PATTERN ATTACHMENT Joe T. Short, West Point, Ga, assignor to Callaway Mills Company, La Grange, Ga. Continuation-impart of application Ser. No. 544,559, Apr. 22, 1966. This application Apr. 18, 1967, Ser. No. 631,806

Int. Cl. D05c 15/00, 23/00;G01n 21/30 US. Cl. 11279 14 Claims ABSTRACT OF THE DISCLOSURE A tufting machine pattern attachment, controlling yarn feed rates for providing yarn loops of corresponding, different heights to produce a desired pattern, includes means enabling change of yarn feed rate only during a preselected interval of each cycle of motion of tufting needles.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 544,559 of Joe T. Short, filed Apr. 22, 1966, entitled Pattern Attachment, and assigned to the assignee of the present application, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a pattern attachment for a tufting machine, and more particularly to a pattern attachment for a tufting machine which provides improved pattern definition in the tufting of a patterned tufted fabric.

Description of the prior art In the tufting art, there are a variety of pattern attachments which are used with a tufting machine to provide yarn of different lengths to the needles of the tufting machine so that the tufting machine will form the yarn loops of different heights which define a tufted fabric pattern. These pattern attachments characteristically include a feeding means for feeding yarn to the needles of a tufting machine at various yarn feed rates and a control means for controlling the feeding means so as to selectively change the yarn feed rate at which yarn is fed to a needle, or to a group of needles, from one of these yarn feed rates to another. The yarn feed rates selectively provided by a pattern attachment are dependent upon the heights of the yarn loops which it is desired for the needles to form during the operation of the tufting machine and which are required for a particular tufted fabric pattern.

A diificulty with these prior art pattern attachments is that the changing by the control means of the yarn feed rates at which yarn is fed to the needles of a tufting machine is often not sufficiently well coordinated with the motion of the needles to provide tufted fabrics having good pattern definition in terms of well defined changes within longitudinal rows of yarn loops between the height of the yarn loops in a pattern area having yarn loops of one desired height and the height of yarn loops in an adjacent pattern area having yarn loops of a different desired height. This is because the lack of adequate coordination between the changing of yarn feed rates and the motion of the needles causes or permits, a required change in yarn feed rate to occur at any time during a cycle of motion of the needles, including the yarn loop forming portion of the cycle, and, further, permits the time of change of the yarn feed rate to vary during different cycles. Thus, the heights of yarn loops obtained, as a change in yarn feed rate occurs, may be of any of many heights other than that desired for one of the pat- Patented Apr. 1, 1969 SUMMARY OF THE INVENTION These and other defects and difficulties of prior art pattern attachments are overcome by the pattern attachment of the invention. The pattern attachment invention disclosed herein provides a control system having means for preventing the occurrence of a change in yarn feed rate in other than a predetermined fixed interval in each cycle of motion of the needles of a tufting machine. With proper selection of this interval, a change in yarn feed rate can occur only with the needles of the tufting machine in that position which will result in yarn loops of desired heights being formed. This insures that there are none of those yarn loops of undesired heights within the longitudinal rows of a tufted fabric which have often prevented good pattern definition with prior .art pattern attachments.

The tufting machine is operable to produce a plurality of successive yarn loops in a backing material in a plurality of corresponding successive cycles of operation. The machine includes pattern means defining diilerent desired heights of the yarn loops to be produced and feed means for feeding yarn at a plurality of different rates for producing yarn loops of corresponding different heights. The control system includes sensor means for sensing the yarn loop heights defined by the pattern means and control means responsive to the sensor means for controlling the said feed means to provide a yarn feed rate corresponding to each yarn loop height defined by the pattern means. The control system further includes selector means responsive to the cyclical operation of the tufting machine to normally disable the control means from changing the yarn feed rate, and to enable the control means to change the yarn feed rate during a preselected interval in each cycle of operation.

This improvement in the tufting art therefore is provided by normally rendering the control means of a pattern attachment inoperative to change the yarn feed rate except during that predetermined interval in a cycle of motion of the needles of a tufting machine best suited to result in the forming of yarn loops of desired heights. Thus, it is impossible for the pattern attachment to change a yarn feed rate in such a manner as to result in a yarn loop of undesired height being formed.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of the invention will be more clearly understood from the following detailed description and the accompanying drawings in which like characters of reference design-ate corresponding parts throughout and in which:

FIG. 1 is a perspective view of those portions of a tufting machine and of a pattern attachment sufiicient to facilitate an understanding of the invention;

FIG. 2 is an enlarged cross-sectional view showing details of portions of the tufting machine of FIG. 1;

FIG. 3 is a schematic presentation of the invention disclosed herein;

FIG. 4 is a schematic presentation of an alternative embodiment of the invention;

FIG. 5 is a block diagram of a further alternative embodiment of the control system of the invention; and

FIG. 6 comprises a circuit schematic corresponding to the block diagram of FIG. 4.

These figures and the following detailed description disclose specific embodiments of the invention, but the invention is not limited to the details disclosed since the invention may be embodied in other equivalent forms.

3 DETAILED DESCRIPTION OF THE DRAWINGS The invention disclosed herein is an improvement in prior art pattern attachments for tufting machines and the invention is most easily understood in terms of a tufting machine 10 such as that discolsed in the United States patent to Short, No. 3,089,442, to which reference is made and in terms of a pattern attachment 11 having a feeding means F and a control means C and of the general type illustrated in the United States patent to Hammel, No. 3,103,187, or in the United States patent to Card, No. 2,862,465, to both of which reference is also made. The patent to Short discloses the tufting machine 10 as having a plurality of hollow needles 12 carried by a needle carrier 13 which is supported by shank 13a and thereby is reciprocated by the rotation of a crank shaft 14 within an upper housing 15.

FIG. 2 comprises a cross-sectional view of portions of the tufting machine 10 of FIG. 1, facilitating an understanding of the operation thereof, particularly as regards the tufting operation of the hollow needles 12. The needle carrier 13 defines an interior pressure chamber 43 suitably connected to an air pressure supply line 44 which defines a fluid flow passage 45 in communication with the pressure chamber 43 of the needle carrier 13. Only a single one of the plurality of individual tufting needles 12 is shown in FIG. 2; it is understood that a plurality of the tufting needles 12 may be supported by the needle carrier 13. Each tufting needle 12 defines an interior delivery channel 47, and includes a plurality of ports 46 whereby the delivery channel 47 communicates with the pressure chamber 43 of the carrier 13.

Plate 48 is mounted by bracket 49 to suitable supports of the tufting machine and includes an aperture 48a corresponding to each of the needles 12. The carrier 13 is reciprocated by actuation of the support shank 13a to project the needles 12. through their corresponding apertures 48a and thereby to penetrate the backing material 50.

Referring concurrently to FIGS. 1 and 2, fluid (not shown) from a fluid source (not shown) is provided through the passage 45 of the supply line 4-4 to the pressure chamber 43 and through the ports 46 to the delivery channel 47 of each tufting needle 12. Yarn 16 is supplied by various supply means of the pattern attachment 11 to corresponding one of the needles 12. As the needles 12 penetrate the backing material 50, the fluid pressure projects the yarn 16 through both the hollow needles and the backing material 50 to form yarn loops, as indicated.

It will be understood that the length of yarn 16 impelled through a hollow needle 12 to form a yarn loop determines the height of the yarn loop and is dependent upon the length of the yarn 16 fed to the hollow needles 12 by the pattern attachment 11 as the yarn loop is being formed.

A pattern attachment 11 of the general type disclosed in the United States patent to Hammel, No. 3,103,187, or in the United States. patent to Card. No. 2,862,465, includes the feeding means P such as a plurality of paired feed rolls 17 which are driven through either a high speed clutch 18 or low speed clutch 19. Each pair of feed rolls 17 feeds yarn 16 from a yarn source (not shown) through a guide plate 20 mounted on the upper housing 15 to a plurality of hollow needles 12 so that identical yarn loops are formed by the hollow needles 12 fed by a particular pair of feed rolls 17. However, the yarn loops formed by the hollow needles 12 fed by one pair of feed rolls 17 will differ from the yarn loops formed by the hollow needles 12 fed by another pair of feed rolls 17 if one pair of feed rolls 17 is being driven through a high speed clutch 18 and the other pair of feed rolls is being driven through a low speed clutch 19.

Each clutch 18 or 19 is a magnetic clutch of known type and serves to operatively connect the central shaft 60 of a feed roll 17 in each pair of feed rolls 17 to a drive shaft 21 extending the length of the tufting machine 11) when the clutch 18 or 19 is energized through an appropriate circuit. The drive shaft 21 is in turn driven by the crank shaft 14 of the tufting machine It} so that the rotational speed of the feed rolls 17 is related to the operating speed of the tufting machine 10. However, for any given operating speed of the tufting machine 10, the rotational speed of each pair of feed rolls 17 depends upon whether the pair of feed rolls 17 is driven through a high speed clutch 18 or a low speed clutch 19. Thus, by selectively energizing the clutches 18 and 19 and driving the feed rolls 17 through either a high speed clutch 18 or low speed clutch 19, the lengths of yarn 16 fed to the hollow needle 12 are varied to provide for yarn loops of the varying height required for a tufted fabric attern.

It is the control means C that provides for the selective energizing of either a high speed clutch 18 or a low speed clutch 19 and in the patent to Hammel, the control means C selectively energizes the clutches 18 and 19 through an appropriate circuit arrangement by the light impinging upon a plurality of photocells 20 arranged adjacent a translucent and opaque drum 22. The drum 22 may be rotated through an appropriate gear box 23 by the crank shaft 14 and the presence or absence of an opaque area on the drum 22 determines which clutch 18 or 19 is energized. In the patent to Card, a drum having a surface with conductive and nonconductive areas and is engaged by fingers to energize the clutches 1S and 19 in accordance with whether a finger is engaging a conductive or nonconductive area. However, in both the pattern attachment of Hammel and that of Card, a pattern on a drum 22 of a similar device serves to selectively energize either a high speed clutch 18 or a low speed clutch 19 through an appropriate circuit arrangement. The general details of such a pattern attachment 11 and of the tufting machine 10 will be understood by those skilled in the art, and it is for this reason that the structural details of the tufting machine 10 and of the pattern attachment 11 are only briefly shown and described herein.

It is also for this reason that a clear understanding of the invention disclosed herein may be obtained from FIG. 3 since FIG. 3 schematically shows the invention in terms of a circuit arrangement which relates the tufting machine 11) and a pattern attachment 11 so as to embody the invention. From FIG. 3 it will be understood that the control means C of the pattern attachment 11 includes a plurality of switching means 24 and that each switching means 24 has a contact arm 25 which in that position indicated by solid line in FIG. 3 provides a first condition or position of the switching means 24 in which the switching means 24 operatively connects the high speed clutch 18 associated with a feed roll 17 to a power source 26. Thus, in its first position each switching means 24 serves to energize a high speed driving means such as a high speed clutch 18 which in turn serves to drive a pair of feed rolls 17 at a particular rotational speed to provide a particular yarn feed rate.

It will also be understood from FIG. 3 that the contact arm 25 of each switching means 24 has another position indicated by dashed line in FIG. 3 in which it provides the switching means 24 with a second condition or position that operatively connects the low speed clutch 19 associated with a feed roll 17 to the power source 26. Thus, in its second position, each switching means 24 serves to energize a low speed driving means such as a low speed clutch 19 which in turn serves to drive a pair of feed rolls 17 at a rotational speed less than that at Which the pair of feed rolls 17 is driven when the high speed clutch 18 is energized. This arrangement of a switching means 24 to selectively energize a plurality of clutches, such as a high speed clutch 18 or a low speed clutch 19, associated with a pair of feed rolls 17 and thereby feed yarn 16 to a hollow needle 12 at any of the plurality of yarn feed rates is conventional. To summarize, the switching means 24 is operable to be selectively switched to first and second states corresponding to the first and second positions of the switch member, or contact arms 25, to selectively energize the clutches 18 and 19, respectively, and thereby selectively provide first and second yarn feed rates. It will be appreciated that switching means may be selectively switched to any of a plurality of states to provide any of a corresponding plurality of yarn feed rates.

Each contact arm 25 carries a pivotally mounted hook 27 and it is also conventional for the contact arm 25 of each switching means 24 to be resiliently biased into that position which provides the first position of the switching means 24 by a spring 29 extending between the book 27 and a fixed positioned tab 30. A switching coil 31 moves the contact arm 25 from this position to that position in which the contact arm 25 provides the second condition of the switching means 24 when light impinges upon one of the plurality of photocells 20 and causes the coils 3-1 to be connected to the power source 26. It is by this arrangement that an opaque area on the drum 22 results in a pair of feed rolls 17 being driven through a high speed clutch 18 and a translucent area on the drum 22 results in a pair of feed rolls 17 being driven through a low speed clutch 19 so that opaque and translucent areas on the drum 22 provide a tufted fabric pattern resulting from different yarn feed rates. Thus, the photocells 20 comprise sensor means which respond to a pattern means, such as the drum 22, to provide outputs representative of the desired yarn loop heights defined by the pattern mean. The control means thus responds to the pattern means to provide yarn feed rates corresponding to the desired loop heights.

However, unlike conventional pattern attachments, the invention provides a pattern attachment 11 having selector means D for rendering the control means C of the pattern attachment 11 inoperative to change a yarn feed rate from that provided by a clutch 18 to that provided by a clutch 19 or from that provided by a clutch 1-9 to that provided by a clutch 18. In that embodiment of the invention disclosed herein, the selector means D includes a latching member 33 which is pivotable between a latching position in which it engages the book 27 carried by the contact arm 25 of the switching means 24 and a releasing position in which it releases and does not engage the hook 27. Thus, in its latching position, a latching member 33 prevents a switching means 24 from changing from its first condition to its second condition or from its second condition to its first condition.

The selector rn'eans D is normally'operative to disable the control means C from changing the yarn feed rate by disabling the switching operation of switching means 24. However, when the latch 33 is moved to its releasing position, the switching means is enabled to be switched between its first and second states.

Each latching member 33 is maintained in its latching position by a spring 32 extending between the latching member 33 and a fixedly positioned tab 35 and is moved to its releasing position only when one of a plurality of releasing coils 36 is energized with a voltage V. It is by the selective energizing of a releasing coil 36 to permit a switching means 24 to change condition that changes in yarn delivery rate are coordinated by the pattern attachment 11 with the motion of the hollow needles 12.

It will be understood that a change in yarn delivery rate can occur only when a releasing coil 36 is energized and it is by energizing the releasing coils 36 only when a change in yarn delivery rate will be coordinated with the motion of the needles 12 that the selector means D prevents the control means C from causing changes in yarn delivery rate which are not coordinated with the hollow needles 12 of the tufting machine 10. In FIG. 3, the selector means D includes a switch member 38 connected in circuit with all of the releasing coils 36. In its operative position, the switch member 38 serves to energize all of the releasing coils 36 by the voltage V so as to render all of the plurality of latching members 33 inoperative and allow all of the plurality of switching means 24 to become simultaneously operative. Thus, the spring 32 normally maintains the latching members 33 in a first position engaging the switch members 25 to prevent movement thereof, and thereby disable the switching means 24, and the releasing coils 36' are operable, due to energization upon closure of the switch member 38, to move the latching member 33 to a second position, releasing the switch members 25 for movement.

The switch member 38 of FIG. 3 is shown diagrammatically at 38' in FIG. 1, as being fixedly mounted adjacent the upper housing 15 of the tufting machine 10 on a suitable support member (not shown) and in a position in which its actuator 40 is engaged by a rise 41 on a cam member 42 mounted on the crank shaft 14 to rotate with the crank shaft 14. In the tufting machine 10, the crank shaft 14 makes one complete revolution to provide that motion of the hollow needles 12 required for each hollow needle 12 to form a yarn loop (FIG. 2). Thus, each revolution of the crank shaft 14 defines a stitching cycle of operation, or cycle of motion, of the needles 12 of the tufting machine 10 and the operation of the switch member 38 is directly related to this cycle of operation of the tufting machine 10 so that the releasing coils 36 are energized only during a particular interval in the stitching cycle. The interval in the stitching cycle of the tufting machine 10 during which the releasing coils 36 are energized depends upon the positions of the actuator 40 attached to the switch member 38 and the rise 41 relative to each other and may be at the beginning of each stitching cycle or at any other desired position in a stitching cycle.

Thus, the cam member 42 normally maintains switch member 38 in an open position, opening the energizing circuits for releasing coils 36 and thereby disabling the switching means 24. The actuating portion of the cam member 42, such as defined by rise 41, actuates the switch member 38 to the closed position, resulting in energization of releasing coils 36 and thereby enabling the switching means 24 to be switched between its first and second states. This enabling occurs during a preselected interval defined by the position of rise 42 relatively to the crank shaft 14 and thus also corresponding to a selected position in the reciprocating motion of the needle carrier 13 in each cycle of operation.

It will now be understood that the control means C can change the yarn feed rate of a pair of feed rolls 17 in the feeding means F only during that portion of the stitching cycle in which the cam member 42 operates the switch member 38 and that changes in yarn feed rate cannot occur in other than this portion of a stitching cycle. Thus, changes in yarn feed rate occur only during a particular portion or preselected interval of a stitching cycle of operation of a tufting machine 10 and cannot occur before or after this portion of a stitching cycle to cause the length of yarn 16 fed to a hollow needle 12 during a stitching cycle to be other than that provided by the selected yarn feed rates. Further, it will be understood that the yarn feed rate will remain constant at a selected yarn feed rate throughout all portions of a Stitching cycle except in that portion during which a change in yarn feed rate is desired and occurs. It is because of this that the invention provides pattern definition in the longitudinal rows of a tufted fabric not possible wtih prior art pattern attachments.

FIG. 4 comprises a schematic of a control system similar to that of FIG. 3 and in which corresponding elements are indicated by identical, but primed numerals. FIG. 4 illustrates only a single switching means 24', and thus there are shown only a single high speed clutch 18 and a single low speed clutch 19', both operating on shaft 60' on which an associated roll 17 is fixedly mounted. A power supply 26 includes a pair of input terminals 55 to which a suitable source of alternating current is provided. A first pair of output leads 56 of the power supply 26 is connected to a relay driver 57, the latter including a pair of sensing leads 58 connected to corresponding terminals of a light sensitive device 20. A pair of output leads 59 of the relay driver 57 is connected to the terminals of the winding of switching relay solenoid 31.

When the light incident on the photo sensitive device 20', illustratively represented by the arrow, varies due to a change in the pattern of the drum 22, there results a change in the internal resistance of the device 20', to which change the relay driver of control means C responds. For example, in sensing an opaque area, little or no light is incident on the device 20' and the latter has a high internal resistance; upon transition to a transparent portion of the drum 22, and the light incident on the de vice 20 effects a substantial reduction in the internal resistance thereof. The reduced internal resistance may effect an increased flow of current in the leads 58, to which relay driver 57 responds to produce a flow of energizing current through the output leads 59 and the winding of switching coil 31.

The switching means 24' includes a pivoted arm 27' which is fixedly secured to the switch member 25' and corresponds in its function to that of the hook 27 of FIG. 3. Spring 29 normally operates to bias the pivoted arm 27', and thus the switch member 25 to a first position, as indicated in solid lines. However, when switching coil 31 is energized, it is operable to move its corresponding pivoted arm 27 and thus the switch member 25 against the restraining bias of spring 29 from the first position, indicated in solid lines, to the second position, indicated in dotted lines. This switching operation, however, is enabled or disabled, dependent upon the position of the latching member 33'.

Normally, the latching member 33 is in the disabling position indicated and prevents the movement of arm 27 despite energization of relay 31. Latching member 33 is moved to the dotted line position releasing the arm 27 for movement and thereby enabling switching means 24' only during the described preselected interval in which the yarn feed rate may be changed, and in accordance with recognition of desired pattern changes by the control means C. The latching member 33 is effective to maintain the arm 27 in either of the positions to which it may be moved. The predetermined interval, as explained previously, is coordinated with the position of the needles 12 and the carrier 13 and, in turn, the position of rotation of crank shaft 14 which imparts the reciprocating motion to the needles 12.

As explained in FIG. 3, the selector mean D further includes a switch member 38' positioned for actuation by an associated cam member 42 which includes a rise 41, or actuating portion on the outer periphery thereof, and mounted on the cam shaft 14' for rotation in fixed relation therewith. Actuator 40 may be suitably biased to continuously engage the periphery of the cam member 42', and thereby control the position of switch member 38 at all times. The cam member 42 is selectively mounted on the crank shaft 14 whereby the rise 41 may be located at the desired angular position relatively to the shaft 14 to correspond to the interval in the cycle of motion of the needles 12 at which it is desired to enable a change of the yarn feed rate. The actuator 40 thereby engages the rise 41' and moves the switch member 38' to engage its contact and complete an energizing circuit for the winding of the releasing coil 36 during the desired, preselected interval.

When the releasing coil 36' is de-energized, its armature is in the normal position indicated in solid lines, whereby the latching member 33 connected thereto is biased by spring 32 about pivot element 62 to its normal position also indicated in solid lines. In this normal condition, the arm 27 is prevented from changing position, as previously described, and the switching means 24' is disabled. However, during the said interval, the releasing coil 36' is energized to move the latching member 33' to the actuated position indicated in dotted lines, releasing the arm 27 for movement and thereby enabling the switch 24' to be switched between its first and second states or positions.

During the preselected interval, therefore, the switching means 24' is enabled to permit change of the rate of yarn feed. If the arm 27, and thu switch member 25, are in the first position, and switching coil 31 is concurrently energized during the preselected interval, arm 27 will be actuated to switch contact arm 25 to the second position for de-energizing clutch 18 and energizing clutch 19. If switching relay 31 is energized during the next enabling interval, arm 27 is retained in the actuated position by the relay 31'. Conversely, if the switching relay 31 is de-energized during the next enabling interval, arm 27' and thus switch member 25' are switched to the first position by spring 29', thereby energizing clutch 18 and de-energizing clutch 19.

A plurality of the switching means 24 will normally be provided in a practical pattern attachment system, corresponding to a plurality of sensing devices 20 to provide control of the change of yarn feed rate of a corresponding plurality of feed rolls 17, through selective energization of the respectively associated clutches 18 and 19. The plurality of switching means 24' may be controlled by a single, or by respectively associated ones of a plurality of selector means D.

It will be obvious to those skilled in the art that the selector means D may be any of a variety of other arrangements such as an arrangement of AND gates. The switching means 24 also may be a switch arrangement other than that disclosed herein.

The system as set forth in the preceding figures may be characterized in logic terminology. A change in the yarn feed rate may be effected only upon the simultaneous occurrence of two conditions. With reference to FIG. 3, a first condition comprises the sensing from a pattern means, such as the drum 22, to which the control means C responds to produce a change in the yarn feed rate in accordance with the change in the desired loop heights to be produced. A second condition comprises the occurrence of the preselected, exclusive interval of a cycle of operation or motion of the tufting needles, during which the control means C is enabled for changing the yarn feed rate. This interval, as previously described, is preselected relatively to, or in coordination with, each cycle of motion of the tufting needles 12 by the selector means D. It is understood, therefore, that the selector means D also performs the converse functions of enabling, in satisfying the second condition.

FIG. 5 shows, in block diagram form, an arrangement of electrical circuits suitable for performing the control functions of the system of the invention. FIG. 6 shows a suitable electrical circuit for performing the operation of the block diagram system of FIG. 5, and the circuits of FIG. 6 are enclosed by dotted lines and labelled in an identical manner to the corresponding block diagram portions of FIG. 5. The operation of the detailed circuit schematic of FIG. 6 will be readily apparent to those skilled in the art, and thus the block diagram of FIG. 5 and the circuit schematic of FIG. 6 are described concurrently hereafter.

The control means includes sensor means comprising a sensor 65 and a trigger circuit 75. The sensor 65 may be of any suitable type, such as the photocell sensors of FIG. 3; although only a single sensor 65 and corresponding trigger are provided, it is apparent that a plurality of such sensors normally would be provided. The control means also includes a flip-flop 90, a relay driver 95, and a relay 66, the flip'fiop having first and second states and operating through relay driver 95 to establish corresponding first and second states of the relay 66 in accordance with the function of the first and second states of the switching means 24 of FIG. 3. Relay 66, in a first position, completes a first energizing circuit, schematically indicated by lead 67, for energizing the high speed magnetic clutch 70 and a second circuit schematically indicated by lead 68 for energizing the low speed magnetic clutch 71. As shown in more detail in FIG. 6, there is provided a power supply 100 and common leads 101 and 102 which are selectively connected by relay 66- with the leads 67 and 68 to energize the clutches 70 and 71, respectively. The clutches 70 and 71 operate on the shaft 72 to impart corresponding rates of rotary motion to the feed roll 73. The clutches 70 and 71 correspond to the clutches 18 and 19, the shaft 72 to the shaft 60, and the roller 73 to the roller 17 of FIG. 3 and may operate in the identical manner as therein described.

The selector means includes a switch member 69 operated by a cam 69a, in a manner identical to the switch member 38 and cam 42 of FIG. 3, between a closed, enabling position indicated in solid lines and an open, disabling position indicated in dotted lines. The selector means further includes a one-shot multivibrator 87 responsive to the switch member 69, and AND gates '80 and 83 connected between the trigger circuit 75 and the flip-flop 90 of the control means. The AND gates 80 and 83 are correspondingly enabled or disabled in accordance with the enabling or disabling positions of the switch member 69 to enable or disable, respectively, the flip-flop 90 from responding to a change in the desired loop heights sensed from a pattern means (not shown) by the sensor 65 of the control means.

It will be assumed that the pattern means (not shown) defines first and second states corresponding to first and second desired loop heights. For example, as described in relation to FIG. 3, in an embodiment employing photocell sensing, the first and second states are represented, or defined, by opaque and transparent portions, respectively, of the drum 22. The sensor 65 produces first and second sensing signals corresponding to the sensing of dark and light states, or portions, respectively, of a pattern means (not shown). From FIG. 6, it will be appreciated that the first and second sensing signals may comprise ground potential and negative potential signals, respectively. The first and second sensing signals are to be understood to represent any two states defined by a pattern means and, in the present explanation, correspond to relatively greater and smaller loop heights, respectively, requiring corresponding, greater and smaller yarn feed rates. The first and second sensing signals therefore require the selective energization of the high speed clutch 70 and the low speed clutch 71, respectively.

Trigger circuit 75 is connected at its input to the output of sensor 65 and includes first and second output terminals 76 and 77. Trigger circuit 75 produces a first output signal at its first output terminal 76 in response to the first signal condition produced by sensor 65 at its input, and a second output signal at its second output terminal 77 in response to the second signal condition produced by sensor 65 at its input. From FIG. 6, it will be understood that the first and second output signals may each comprise a negative potential signal respectively correspondmg to the ground potential and negative potential signals produced by sensor 65. The trigger circuit 75 maintains these output signals for the duration of the corresponding sensing signals received at its input from the sensor 65.

AND gate 80 includes a first input 81 connected to the output 76 of the trigger circuit 75, and AND gate 83 includes a first input 84 connected to the output 77 of the trigger circuit 75. AND gates 80 and 83 include second inputs 82 and 85, respectively, connected through a common lead 86 to the output of the one-shot multivibrator 87. The input to the multivibrator 87 is connected to a lead 88 associated with the switch member 69.

Switch member 69 operates in a manner identical to that of switch member 38 of FIG. 3, in response to a cam 69a. In the normally open position of switch member 69, no input signal is produced on lead 88; when actuated to its closed position, switch 69 completes a circuit to the negative power supply terminal 89 to produce a negative potential signal on the lead 88. The negative potential signal identifies the occurrence of the preselected interval in each cycle of operation during such changes in the yarn feed rate may occur.

The one-shot multivibrator 87 normally maintains a disable signal on lead 86, and responds to the negative potential, interval-defining signal established on lead 88 to produce an enable pulse on the lead 86. The enable pulse enables each of the AND gates 80 and 83 for applying the first and second output signals respectively applied thereto from trigger circuit to the corresponding first and second inputs 91 and 92 of the flip-flop 90. Thus, for example, if a first output signal is maintained at the first output 76 of trigger circuit 75 during the occurrence of an enable pulse on lead '86, AND gate will thereby be enabled and apply an output signal to the first input 91 of flip-flop 90.

The output signals from AND gates 80 and 83, applied to the first and second inputs 91 and 92, respectively, of flip-flop 90, operate as setting pulses to set the flip-flop to the corresponding one of its first and second bistable states. As a conventional, the flip-flop 90' is set to either of its states, from the opposite state, by a single set pulse applied to the corresponding input terminal and the given set state to which it was last set is thereafter maintained, and is not affected by the subsequent application of additional set pulses to that same input terminal.

Flip-flop 90 is operable in its first state to produce a signal on lead 93 which disables relay driver 95, whereby relay 66 is not energized. In its unenergized or normal state, relay 66 completes the enerigzing circuit 67 for energizing clutch 70, which thereby produces a high yarn feed rate. Conversely, in its second state, flip-flop 90 produces a signal on lead 93 which energizes relay driver 95 to, in turn, energize relay 66 to its actuated position. In its actuated position, relay 66 completes the energizing circuit 68 for energizing low speed clutch 71 to produce a low yarn feed rate. Thus, the state in which flip-flop 90 is set determines which of the clutches 70 and 71 is energized. Further, flip-flop 90 can be switched to a different state in response to a change in the desired loop height, as represented by a change from one to the other of the first and second otuput signals from trigger circuit 75, only when the corresponding one of the AND gates 80 and 83 is concurrently enabled by an enable pulse produced on lead 86 by multivibrator 87, and thus only during the preselected interval.

If desired, and in the alternative to the disclosed embodiment, individual means may be provided for responding to either of the first and second stable states of the flipflop 90 for selectively energizing the clutches 70 and 71, respectively. The modification of the block diagram of FIG. 4, and the corresponding circuit requirements for providing such an alternative embodiments will be readily apparent to those skilled in the art.

In summary, the control system of the invention satisfies a critical need in the functioning of pattern attachments for tufting machines. The various embodiments of the invention herein set forth include both electromechanical and substantially entirely electronic circuits for achieving accurate control of the time of response of a tufting machine to changes in yarn feed rates indicated by a pattern attachment. In particular, this control permits selection of any desired interval of the entire cycle of motion of the tufting needles at which the rate of yarn feed may be changed. By thus correlating, or coordinating, the time of change with the position in the cycle of motion of the tufting needles, greatly improved effects in patterns may be achieved. For example, by permitting the change to be effected only during the interval of the cycle of motion when the needles are displaced from and not penetrating the backing material, extremely well-defined patterns of high and low yarn loops may be obtained. It will be apparent, however, that this interval may be selected during other positions in the cycle of motion of the needles to achieve unique and unusual effects in the development of patterns having a range of desired yarn loop heights, even where only two individual yarn feed means of different, but fixed rates, such as the magnetic clutches described herein, are provided for controlling the rate of yarn feed.

Although the logic diagram and explanation of the control system of the invention has been confined substantially to a simplified form facilitating an explanation of the specific embodiment disclosed, it will be apparent that the unique features of the control system of the invention may be attained by varying the electromechanical and electronic circuits and apparatus employed therein, and additionally by varying or enlarging upon the system as set forth in the logic diagrams. It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims. Thus, it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of the invention.

What is claimed is:

1. In a tufting machine operable to produce a plurality of successive yarn loops in a backing material in a plurality of corresponding successive cycles of operation and having pattern means defining different desired heights of the yarn loops to be produced and feed means for feeding yarn at a plurality of different rates for producing yarn loops of corresponding different heights, a control system comprising:

control means responsive to the pattern means for controlling said feed means to provide a yarn feed rate corresponding to each yarn loop height defined by the pattern means, and

selector means responsive to the cyclical operation of the tufting machine to normally disable said control means from changing the yarn feed rate and to enable control means to change the yarn feed rate during a preselected interval in each cycle of operation.

2. A control system as recited in claim ll, wherein:

said selector means defines only a single preselected interval in each cycle of operation for enabling said control means.

3. A control system as recited in claim 1 wherein said tufting machine further includes at least one t-ufting needle supported in a needle carrier for reciprocating motion between first and second extreme positions remote from and penetrating, respectively, said backing material in each cycle of operation, and wherein:

said selector means enables said control means during a preselected interval corresponding to a predetermined position of said tufting needle in the reciprocating motion thereof.

4. A control system as recited in claim 3 wherein:

said selector means enables said control means when said tufting needle is not penetrating said backing material.

5. A control system as recited in claim 3 wherein said selector means comprises:

a switch having a disabling position in which said switch disables said control means and an enabling position in which said switch enables said control means, and

actuating means operatively associated with said needle carrier to actuate said switch from said disabling position to said enabling position in response to movement of said needle carrier to a selected posi- 12 tion in the reciprocating motion thereof in each cycle of operation.

6. A control system as recited in claim 5, wherein:

said actuating means actuates said switch to said enabling position in response to movement of said needle carrier to said first extreme position.

7. A control system as recited in claim 5 wherein said tufting machine includes a rotatable shaft operatively coupled to said needle carrier for imparting said reciprocating motion thereto, and wherein said actuating means comprises:

a cam member selectively mounted on said shaft for fixed rotation therewith and including an actuating portion located relatively to said shaft to correspond to said selected position in the reciprocating motion of said needle carrier, said cam member normally maintaining said switch in said disabling position thereof to disable said control means and said actuating portion of said cam member actuating said switch to said enabling position thereof to enable said control means.

8. A control system as recited in claim 7 wherein:

said actuating portion of said cam member is located relatively to said shaft to correspond to the first extreme position of said needle carrier.

9. A control system as recited in claim 1 wherein:

said feed means is operative to feed said yarn at first and second different rates for producing yarn loops of corresponding first and second different heights,

said control means comprises switching means operable to be selectively switched to first and second states in response to said pattern means defining first and second heights of yarn loops, respectively, and operable in said first and second states to cause said feed means to feed yarn at said first and second different rates, respectively, and

said selector means normally disables said switching means to prevent switching thereof and enables said switching means to permit switching thereof during said preselected interval.

10. A control svstem as recited in claim 9, wherein:

said feed means comprises a feed roll and first and second driving means independently operative for driving said feed roll at difierent first and second rotational speeds to feed said yarn at different first and second rates, respectively, and

said control means is operable in said first state to render said first driving means operative and is operable in said second state to render said second driving means operative.

11. A control system as recited in claim 9, wherein:

said switching means includes a switch member movable between first and second positions corresponding to said first and second states, respectively, of said switching means, and

said selector means comprises a latching member and means to normally maintain said latching member in a first position engaging said switch member to prevent movement thereof for disabling said switching means, and operable to move said latching member to a second position releasing said switch member during the preselected interval in each cycle of operation for enabling movement of said switch member between said first and second positions thereof.

12. A control system as recited in claim 11, wherein:

said switching means comprises a relay.

13. A .control system as recited in claim 9, wherein:

said control means further includes sensor means for responding to said pattern means to produce first and second output signals corresponding to said first and second heights of yarn loops defined by said pattern means,

said switching means comprises bistable means operable to be selectively switched to, and set in, said first and second states in response to application thereto of said first and second output signals, respectively, of said sensor means, and

said selector means includes gate means connected between said bistable means and said senor means, said gate means being normally disabled to prevent application of said output signals of said sensor means to said bistable means and being enabled during said preselected interval to permit ap- References Cited plication of said output signals of said sensor means to said bistable means for switching said bistable UNITED STATES PATENTS means to the corresponding state. 2,862,465 12/ 1958 Card 11279.6 14. A control system as recited in claim 13, wherein: 2,862,466 12/1958 Bryant et al. 11279 said selector means further includes signal means hav- 3,100,465 8/ 1963 Broadrick 11279 ing an output, said signal means normally produc- 15 3,103,187 9/1963 Hammel 11279 ing a disabling signal at said output and producing 3,172,380 3/1965 Boyles 112-79 an enabling signal at said output during said pre- 3,221,683 12/ 1965 Abelsma 11279 selected interval in each cycle of operation, and 3,247,815 4/1966 Polevitzky 11279 said gate means comprise first and second AND gates each having first and second inputs and an output, HERBERT F. ROSS, Primary Examiner. the first input of said first and second AND gates being connected to said first and second outputs,

respectively, of said sensor means and the second 

